Pub Date : 2019-04-12DOI: 10.17073/0021-3438-2019-2-43-50
K. Y. Chervyakova, A. Yakovleva, N. Belov, I. Shkaley
The article focuses on the actual problem of creating economically alloyed antifriction aluminum alloys doped with low-melting metals. It was found in earlier experiments that an alloy containing about 5 % Si, 4% Cu and 6 % Sn (wt.%) has a balanced complex of technological and physicomechanical properties. Due to the high cost of tin, this paper considers the possibility of reducing its concentration to 4 %, and its partial replacement by other low-melting metals, such as bismuth and lead. Thermodynamic calculations (in the Thermo-Calc program) including the construction of polythermal and isothermal sections are used to study the joint and separate influence ofthese elements on the phase composition of the Al—5%Si—4%Cu—4%Sn alloy. It is shown that the addition of lead and bismuth leads to the appearance of an extensive area of fluid separation, and therefore their total concentration should not exceed 1—2 %. The phase composition and microstructure ofthe Al—5%Si—4%Cu—4%Sn—0,5%Pb—0,5%Bi alloy were studied using scanning electron microscopy and micro X-ray spectral analysis. It was found that in the cast state, low-melting metals are evenly distributed in the structure of the alloy, and in terms of the combination of properties, the experimental aluminum alloys surpass the BrO4Z4S17 antifriction bronze. Heat treatment mode T6 leads to a significant increase in the hardness of the experimental alloy. However, in the process of heating for quenching at 500 °C, local fusion of the low-melting component occurs, which leads to deterioration of the microstructure upon re-crystallization and, as a result, causes alloy embrittlement.
{"title":"Effect of bismuth and lead on phase composition and structure of Al—5%Si—4%Cu—4%Sn alloy","authors":"K. Y. Chervyakova, A. Yakovleva, N. Belov, I. Shkaley","doi":"10.17073/0021-3438-2019-2-43-50","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-2-43-50","url":null,"abstract":"The article focuses on the actual problem of creating economically alloyed antifriction aluminum alloys doped with low-melting metals. It was found in earlier experiments that an alloy containing about 5 % Si, 4% Cu and 6 % Sn (wt.%) has a balanced complex of technological and physicomechanical properties. Due to the high cost of tin, this paper considers the possibility of reducing its concentration to 4 %, and its partial replacement by other low-melting metals, such as bismuth and lead. Thermodynamic calculations (in the Thermo-Calc program) including the construction of polythermal and isothermal sections are used to study the joint and separate influence ofthese elements on the phase composition of the Al—5%Si—4%Cu—4%Sn alloy. It is shown that the addition of lead and bismuth leads to the appearance of an extensive area of fluid separation, and therefore their total concentration should not exceed 1—2 %. The phase composition and microstructure ofthe Al—5%Si—4%Cu—4%Sn—0,5%Pb—0,5%Bi alloy were studied using scanning electron microscopy and micro X-ray spectral analysis. It was found that in the cast state, low-melting metals are evenly distributed in the structure of the alloy, and in terms of the combination of properties, the experimental aluminum alloys surpass the BrO4Z4S17 antifriction bronze. Heat treatment mode T6 leads to a significant increase in the hardness of the experimental alloy. However, in the process of heating for quenching at 500 °C, local fusion of the low-melting component occurs, which leads to deterioration of the microstructure upon re-crystallization and, as a result, causes alloy embrittlement.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81402977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-12DOI: 10.17073/0021-3438-2019-2-13-25
I. Komelin, A. P. Lysenko
The paper provides a review of the literature on the interaction of magnesium production salt melts with atmospheric air. The method for measuring the mass of reaction products of the molten salt with air is described. The results of investigation of hydrogen chloride and chlorine emission intensity by salt melts of MgCl 2 -KCl-NaCl, MgCl 2 -KCl-NaCl-BaCl 2 , MgCl 2 —KCl—NaCl—CaCl 2 systems, as well as the intensity of HCl + HBr and Cl 2 + Br 2 gas emission by MgCl 2 —KCl—NaCl—NaBr system salt melts are presented. Thermodynamic analysis of reactions of interaction of magnesium salt melts with atmospheric air is carried out. It is determined that magnesium chloride in salt melt interacts with atmospheric air most intensively with the release of chlorine and hydrogen chloride. Specific rates of halogen-containing gases formation per unit surface area of the MgCl 2 -KCl-NaCl, Mga 2 -KCl-NaCl-BaCl 2 , MgCl 2 -KCl-NaCl-CaCl 2 , MgCl 2 -KCl-NaCl-NaBr systems are measured. The influence of calcium chloride, sodium bromide and magnesium fluoride on the intensity of halogen-containing gases emission by the surface of salt melts is studied. It is found that the addition of magnesium fluoride in the composition of chloride melts reduces the intensity of chlorine and hydrogen chloride emission.
{"title":"Interaction of magnesium production salt melts with atmospheric air","authors":"I. Komelin, A. P. Lysenko","doi":"10.17073/0021-3438-2019-2-13-25","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-2-13-25","url":null,"abstract":"The paper provides a review of the literature on the interaction of magnesium production salt melts with atmospheric air. The method for measuring the mass of reaction products of the molten salt with air is described. The results of investigation of hydrogen chloride and chlorine emission intensity by salt melts of MgCl 2 -KCl-NaCl, MgCl 2 -KCl-NaCl-BaCl 2 , MgCl 2 —KCl—NaCl—CaCl 2 systems, as well as the intensity of HCl + HBr and Cl 2 + Br 2 gas emission by MgCl 2 —KCl—NaCl—NaBr system salt melts are presented. Thermodynamic analysis of reactions of interaction of magnesium salt melts with atmospheric air is carried out. It is determined that magnesium chloride in salt melt interacts with atmospheric air most intensively with the release of chlorine and hydrogen chloride. Specific rates of halogen-containing gases formation per unit surface area of the MgCl 2 -KCl-NaCl, Mga 2 -KCl-NaCl-BaCl 2 , MgCl 2 -KCl-NaCl-CaCl 2 , MgCl 2 -KCl-NaCl-NaBr systems are measured. The influence of calcium chloride, sodium bromide and magnesium fluoride on the intensity of halogen-containing gases emission by the surface of salt melts is studied. It is found that the addition of magnesium fluoride in the composition of chloride melts reduces the intensity of chlorine and hydrogen chloride emission.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88067897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-12DOI: 10.17073/0021-3438-2019-2-35-42
V. Glushchenkov, I. Belyaeva, F. Grechnikov, V. Mironov, Y. Usherenko, V. I. Pesotsky
The article considers the compaction of Al-B-W system powder in a copper shell. Such material is supposed to be used, for example, to produce grinding tool components or radiation protection elements. For this purpose, it is necessary to obtain both short and long-length semi-finished products which required the development and testing of various technological schemes (technologies) based on the use of static, dynamic loads and their combinations. Analysis of the results of the experiments showed reality and the possibility of implementing the proposed schemes to obtain tubular semi-finished products of different sizes. The whole chain of their manufacturing from powder production to compaction and sintering is considered. Metallographic studies conducted to assess the quality of sintered powder composition demonstrated almost full absence of pores. The technology is developed to ensure making new products, including long-length ones, from powder composition.
{"title":"Compaction methods for Al—B—W powder composition in a metal shell","authors":"V. Glushchenkov, I. Belyaeva, F. Grechnikov, V. Mironov, Y. Usherenko, V. I. Pesotsky","doi":"10.17073/0021-3438-2019-2-35-42","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-2-35-42","url":null,"abstract":"The article considers the compaction of Al-B-W system powder in a copper shell. Such material is supposed to be used, for example, to produce grinding tool components or radiation protection elements. For this purpose, it is necessary to obtain both short and long-length semi-finished products which required the development and testing of various technological schemes (technologies) based on the use of static, dynamic loads and their combinations. Analysis of the results of the experiments showed reality and the possibility of implementing the proposed schemes to obtain tubular semi-finished products of different sizes. The whole chain of their manufacturing from powder production to compaction and sintering is considered. Metallographic studies conducted to assess the quality of sintered powder composition demonstrated almost full absence of pores. The technology is developed to ensure making new products, including long-length ones, from powder composition.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73820307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-12DOI: 10.17073/0021-3438-2019-2-26-34
A. P. Skuratov, A. S. Potapenko, Yuriy V. Gorokhov, N. P. Popiyakova
The article presents the results of a numerical study of temperature-time dependences in continuous combined casting and pressing of the AK12 experimental aluminum alloy, which has a different overheating temperature, in the time interval from start-up to the moment of the unit reaching the stationary thermal regime. Calculations are carried out on the basis of a three-dimensional computer model of complex heat transfer in the unit of a new design equipped with a horizontal carousel crystallizer. Theoretical studies are conducted to determine the influence of superheating of poured aluminum melt on the processes of unsteady heat transfer. The influence of the nature of heat transfer in the transient thermal regime on the temperature field of the solidifying melt at different distances from the pour point is determined. It is shown that as the crystallizer heats up in the transition process, the asymmetry of the temperature field in the control section of metal increases near the pressing tool with the shift of the maximum temperature region to the crystallizer contac surface. It is found that the transition process duration when starting the unit in a cold state until it reaches a stationary thermal regime depends on the temperature of poured melt. The maximum limit of the overheating value is determined, above which poured metal, when implementing the technology of continuous combined casting and pressing, aluminum melt does not solidify in the crystallizer and forced cooling of unit elements must be arranged. The influence of melt overheating on the pattern of the temperature field along the crystallizer cross section over the entire period of the transient thermal process is estimated. Design measures to ensure rational temperature conditions of bearings during the unit operation are determined.
{"title":"Numerical investigation of influence of molten aluminum overheating on heat transfer in continuous combined casting and pressing","authors":"A. P. Skuratov, A. S. Potapenko, Yuriy V. Gorokhov, N. P. Popiyakova","doi":"10.17073/0021-3438-2019-2-26-34","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-2-26-34","url":null,"abstract":"The article presents the results of a numerical study of temperature-time dependences in continuous combined casting and pressing of the AK12 experimental aluminum alloy, which has a different overheating temperature, in the time interval from start-up to the moment of the unit reaching the stationary thermal regime. Calculations are carried out on the basis of a three-dimensional computer model of complex heat transfer in the unit of a new design equipped with a horizontal carousel crystallizer. Theoretical studies are conducted to determine the influence of superheating of poured aluminum melt on the processes of unsteady heat transfer. The influence of the nature of heat transfer in the transient thermal regime on the temperature field of the solidifying melt at different distances from the pour point is determined. It is shown that as the crystallizer heats up in the transition process, the asymmetry of the temperature field in the control section of metal increases near the pressing tool with the shift of the maximum temperature region to the crystallizer contac surface. It is found that the transition process duration when starting the unit in a cold state until it reaches a stationary thermal regime depends on the temperature of poured melt. The maximum limit of the overheating value is determined, above which poured metal, when implementing the technology of continuous combined casting and pressing, aluminum melt does not solidify in the crystallizer and forced cooling of unit elements must be arranged. The influence of melt overheating on the pattern of the temperature field along the crystallizer cross section over the entire period of the transient thermal process is estimated. Design measures to ensure rational temperature conditions of bearings during the unit operation are determined.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90053445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-22DOI: 10.17073/0021-3438-2019-1-4-15
A. Lavrinenko, D. Makarov, L. M. Sarkisova, N. I. Glukhova, É. A. Shrader, I. Kuznetsova
The paper provides the results of studies into the interaction between Aerophine 3418A, Aerophine 3416, Aerophine 3406 collectors containing diisobutyldithiophosphinate (DIP) and butyl xanthate with pyrrhotite, pentlandite, platinum black and cooperite by measuring the electrode potential and determination of DIP adsorption forms using extractive spectrophotometry. It was shown that butyl xanthate reduces the electrode potential to a greater extent compared to DIP-containing collectors. The value of electrode potential shift in the presence of collectors decreases in the series: platinum black — pentlandite — pyrrhotite. Pentlandite and pyrrhotite interaction with butyl xanthate and DIP mainly results in the molecular form - disulfide - formed on the surface with the order of magnitude less compounds of collectors with metal. After interaction with butyl xanthate, the sorption layer on cooperite contained disulfide only, and both disulfide and the complex compound of Pt with DIP in case of DIP. It was demonstrated that DIP containing collectors have a greater collecting and hydrophobic ability than butyl xanthate to pentlandite and pyrrhotite. The maximum hydrophobic effect is achieved using a composition of butyl xanthate and DIP-containing collectors with a ratio of 1:1 to 1:3. The effectiveness of Aerophine 3416 and butyl xanthate compositions in bulk flotation of platinum-copper-nickel ores is shown.
{"title":"The influence of collectors containing diisobutyldithiophosphinate on the flotation of sulfides and platinum-group metals of copper-nickel ores","authors":"A. Lavrinenko, D. Makarov, L. M. Sarkisova, N. I. Glukhova, É. A. Shrader, I. Kuznetsova","doi":"10.17073/0021-3438-2019-1-4-15","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-1-4-15","url":null,"abstract":"The paper provides the results of studies into the interaction between Aerophine 3418A, Aerophine 3416, Aerophine 3406 collectors containing diisobutyldithiophosphinate (DIP) and butyl xanthate with pyrrhotite, pentlandite, platinum black and cooperite by measuring the electrode potential and determination of DIP adsorption forms using extractive spectrophotometry. It was shown that butyl xanthate reduces the electrode potential to a greater extent compared to DIP-containing collectors. The value of electrode potential shift in the presence of collectors decreases in the series: platinum black — pentlandite — pyrrhotite. Pentlandite and pyrrhotite interaction with butyl xanthate and DIP mainly results in the molecular form - disulfide - formed on the surface with the order of magnitude less compounds of collectors with metal. After interaction with butyl xanthate, the sorption layer on cooperite contained disulfide only, and both disulfide and the complex compound of Pt with DIP in case of DIP. It was demonstrated that DIP containing collectors have a greater collecting and hydrophobic ability than butyl xanthate to pentlandite and pyrrhotite. The maximum hydrophobic effect is achieved using a composition of butyl xanthate and DIP-containing collectors with a ratio of 1:1 to 1:3. The effectiveness of Aerophine 3416 and butyl xanthate compositions in bulk flotation of platinum-copper-nickel ores is shown.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79011205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-22DOI: 10.17073/0021-3438-2019-1-75-81
O. Abonosimov, S. I. Lazarev, S. Kotenev, I. Selivanov, K. Polyanskiy
The paper considers the potential practical application of an electrochemical membrane method in the process of copper sulfate and trisodium phosphate removal from industrial water. The research objects were process solutions containing copper sulfate and trisodium phosphate and semipermeable polymeric membranes with various selective permeability characteristics. The study covers the effect that the transmembrane parameters of electromembrane separation have on the main kinetic characteristics of MGA-95P and OPM-K membranes in the process of copper smelting production water treatment. Approximation expressions were obtained to calculate membrane rejection rate depending on the physicochemical basis of the semipermeable membrane polymer, transmembrane pressure as well as process solution concentration and temperature. Empirical coefficients were determined to calculate and predict rejection rate values that can be used in the design of laboratory, pilot and industrial units used in the separation, treatment and concentration of industrial and waste water. The mathematical model of mass transfer was developed for electrochemical membrane separation taking into account assumptions made based on the solutions of the Nernst—Planck and Poisson—Boltzmann equations. This model allows for process physical description and calculations of concentration fields in the intermembrane channel and concentration changes in permeate and retentate lines. The mathematical model was checked for adequacy by comparing experimental data on retention rate with theoretical values where discrepancies between the experimental and theoretical data were within the limits of the experimental error and the error of calculated values.
{"title":"Efficiency of electrochemical membrane cleaning of process solutions from copper sulphate and trisodium phosphate","authors":"O. Abonosimov, S. I. Lazarev, S. Kotenev, I. Selivanov, K. Polyanskiy","doi":"10.17073/0021-3438-2019-1-75-81","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-1-75-81","url":null,"abstract":"The paper considers the potential practical application of an electrochemical membrane method in the process of copper sulfate and trisodium phosphate removal from industrial water. The research objects were process solutions containing copper sulfate and trisodium phosphate and semipermeable polymeric membranes with various selective permeability characteristics. The study covers the effect that the transmembrane parameters of electromembrane separation have on the main kinetic characteristics of MGA-95P and OPM-K membranes in the process of copper smelting production water treatment. Approximation expressions were obtained to calculate membrane rejection rate depending on the physicochemical basis of the semipermeable membrane polymer, transmembrane pressure as well as process solution concentration and temperature. Empirical coefficients were determined to calculate and predict rejection rate values that can be used in the design of laboratory, pilot and industrial units used in the separation, treatment and concentration of industrial and waste water. The mathematical model of mass transfer was developed for electrochemical membrane separation taking into account assumptions made based on the solutions of the Nernst—Planck and Poisson—Boltzmann equations. This model allows for process physical description and calculations of concentration fields in the intermembrane channel and concentration changes in permeate and retentate lines. The mathematical model was checked for adequacy by comparing experimental data on retention rate with theoretical values where discrepancies between the experimental and theoretical data were within the limits of the experimental error and the error of calculated values.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83977237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-22DOI: 10.17073/0021-3438-2019-1-59-66
N. Yu.Loginov, A. Yu
Deformation patterns of rolling, equal-channel angular pressing and non-equal-channel angular pressing were evaluated. It is noted that when rolling, it is difficult to transfer a circular section preform into a rectangular section with a small thickness. This problem cannot be solved using equal-channel angular pressing. In connection with this, it is proposed to use a non-equal-channel angular pressing pattern to study the cast structure of magnesium. An experimental procedure based on cold extrusion of cylinders with a diameter of 42 mm and a height of 40 mm is described. The strip at the outlet was 40 mm in width and 1 mm in thickness. The percentage reduction of the preform material determined by the ratio of areas was 96 % with a draw ratio of 17. The specific pressures on the punch at the beginning ofthe extrusion process were 1200—1300 MPa, and extrusion force was 1670—1800 kN. The preform was cut into lengths that were rolled at a room temperature into 50 and 10 pm thick foils without intermediate annealing. Rolling was carried out on the Duo mill with a percentage reduction of 12—20 % at an average speed of 0,1 m/s. 20 passes were performed with a total relative reduction of 95 % to make the 50 pm thick foil. The results of computer simulation by the finite element method demonstrated that the constant value of the deformation degree is achieved at a rather considerable distance from the front end estimated as 50 times the thickness of the strip. The deformation rate field was calculated to determine the configuration of the deformation center. Energy costs were estimated. As a result of the completed set of calculated and experimental work, it was possible to establish the following — it is possible to produce a thin sheet preform from a cylindrical cast magnesium blank in one operation at a room temperature. The sheet blank has a level of ductility sufficient for subsequent sheet rolling. The sheet blank obtained in the proposed process has a high level of plastic deformation elaboration created due to the forming pattern with the high level of elongation and shear deformation. Despite the high level of pressure that must be applied to create a comprehensive compression scheme taking into account the lack of the need to heat the preform, energy costs are no higher than in traditional treatment processes.
{"title":"Analysis of non-equal-channel angular pressing scheme applied for obtaining magnesium sheet in cold state","authors":"N. Yu.Loginov, A. Yu","doi":"10.17073/0021-3438-2019-1-59-66","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-1-59-66","url":null,"abstract":"Deformation patterns of rolling, equal-channel angular pressing and non-equal-channel angular pressing were evaluated. It is noted that when rolling, it is difficult to transfer a circular section preform into a rectangular section with a small thickness. This problem cannot be solved using equal-channel angular pressing. In connection with this, it is proposed to use a non-equal-channel angular pressing pattern to study the cast structure of magnesium. An experimental procedure based on cold extrusion of cylinders with a diameter of 42 mm and a height of 40 mm is described. The strip at the outlet was 40 mm in width and 1 mm in thickness. The percentage reduction of the preform material determined by the ratio of areas was 96 % with a draw ratio of 17. The specific pressures on the punch at the beginning ofthe extrusion process were 1200—1300 MPa, and extrusion force was 1670—1800 kN. The preform was cut into lengths that were rolled at a room temperature into 50 and 10 pm thick foils without intermediate annealing. Rolling was carried out on the Duo mill with a percentage reduction of 12—20 % at an average speed of 0,1 m/s. 20 passes were performed with a total relative reduction of 95 % to make the 50 pm thick foil. The results of computer simulation by the finite element method demonstrated that the constant value of the deformation degree is achieved at a rather considerable distance from the front end estimated as 50 times the thickness of the strip. The deformation rate field was calculated to determine the configuration of the deformation center. Energy costs were estimated. As a result of the completed set of calculated and experimental work, it was possible to establish the following — it is possible to produce a thin sheet preform from a cylindrical cast magnesium blank in one operation at a room temperature. The sheet blank has a level of ductility sufficient for subsequent sheet rolling. The sheet blank obtained in the proposed process has a high level of plastic deformation elaboration created due to the forming pattern with the high level of elongation and shear deformation. Despite the high level of pressure that must be applied to create a comprehensive compression scheme taking into account the lack of the need to heat the preform, energy costs are no higher than in traditional treatment processes.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82648981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-22DOI: 10.17073/0021-3438-2019-1-50-58
I. Ganiev, A. G. Safarov, F. R. Odinaev, U. Yakubov, K. Kabutov
It is known that commercial aluminum with a high content of iron, silicon and other impurities has no industrial application because of low performance. Hence, the development of new alloy compositions based on such a metal is a very urgent task. Promising compositions in the Al—Fe diagram are the (a-Al + A 3 Fe) eutectic and hypereutectic compositions that correspond to an iron content of 2—5 wt.% due to a minimum range of crystallization temperature. An alloy with the composition Al + 4,5 % Fe (AlFe4,5) was taken as a model alloy and subjected to modification with tin. The paper experimentally determined the dependence of specific heat of the Al + 4,5 % Fe alloy doped with tin with the calculation of changes in its thermodynamic functions. Studies were carried out in a «cooling» mode using computer equipment and the Sigma Plot program. The polynomials of the temperature dependence of the specific heat and changes in thermodynamic functions (enthalpy, entropy, and Gibbs energies) were determined for Al + 4,5 % Fe alloys doped with tin and basic reference standard (Cu) defined by the correlation coefficient R corr = 0,999. It was found that the heat capacity of the initial alloy decreases with an increasing tin content and increases as temperature rises. The enthalpy and entropy of the Al + 4,5 % Fe alloy increase with rising tin content and temperature, while the Gibbs energy decreases.
{"title":"Temperature dependence of specific heat and thermodynamic functions of Al + 4,5 % Fe alloys doped with tin","authors":"I. Ganiev, A. G. Safarov, F. R. Odinaev, U. Yakubov, K. Kabutov","doi":"10.17073/0021-3438-2019-1-50-58","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-1-50-58","url":null,"abstract":"It is known that commercial aluminum with a high content of iron, silicon and other impurities has no industrial application because of low performance. Hence, the development of new alloy compositions based on such a metal is a very urgent task. Promising compositions in the Al—Fe diagram are the (a-Al + A 3 Fe) eutectic and hypereutectic compositions that correspond to an iron content of 2—5 wt.% due to a minimum range of crystallization temperature. An alloy with the composition Al + 4,5 % Fe (AlFe4,5) was taken as a model alloy and subjected to modification with tin. The paper experimentally determined the dependence of specific heat of the Al + 4,5 % Fe alloy doped with tin with the calculation of changes in its thermodynamic functions. Studies were carried out in a «cooling» mode using computer equipment and the Sigma Plot program. The polynomials of the temperature dependence of the specific heat and changes in thermodynamic functions (enthalpy, entropy, and Gibbs energies) were determined for Al + 4,5 % Fe alloys doped with tin and basic reference standard (Cu) defined by the correlation coefficient R corr = 0,999. It was found that the heat capacity of the initial alloy decreases with an increasing tin content and increases as temperature rises. The enthalpy and entropy of the Al + 4,5 % Fe alloy increase with rising tin content and temperature, while the Gibbs energy decreases.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80250774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-22DOI: 10.17073/0021-3438-2019-1-25-33
N. Kulenova, Z. Akhmetvalieva, S. Mamyachenkov, O. S. Anisimova
The results of a study on the disposal of waste discharge at the iron and steel works using centrifugation and vacuum sublimation methods are presented. The object of the study was industrial effluents of titanium-magnesium production. The influence of centrifuge rotation speed, duration, temperature and fraction of solid phase on the process of industrial effluent separation into liquid (fugate) and solid (sediment) phases is studied. A complex of studies based on the multifactor experiment design was carried out to evaluate the effect of each of these factors. Optimum centrifugation parameters were established: rotor speed — 3000 rpm and duration — 30 min. The obtained solution (fugate) contained 195 mg/dm 3 of suspended matter, 26500 mg/dm 3 of chlorides, 39750 mg/dm 3 of dry residue, which indicates its high mineralization and the need for further purification. The expediency of a thermal method of fugate demineralization using a rotary vacuum evaporator was demonstrated in laboratory conditions. Optimum process parameters were determined: temperature 70 ° С , residual pressure — less than 50 mbar, duration — 30 min. Residue yield after vacuum sublimation was 6 % of the fugate weight. No suspended substances were found in the obtained condensate, and chloride content was 50 mg/dm 3 . The proposed technology for the disposal of industrial effluents at titanium-magnesium production will facilitate forming a closed water supply cycle at the enterprise. Residue obtained after the fugate vacuum sublimation containing mainly chlorides of alkali and alkaline earth metals can be recommended to use as an additive for the preparation of anti-ice materials, as well as drilling fluids and kill mud.
{"title":"Disposal of titanium-magnesium production industrial effluents","authors":"N. Kulenova, Z. Akhmetvalieva, S. Mamyachenkov, O. S. Anisimova","doi":"10.17073/0021-3438-2019-1-25-33","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-1-25-33","url":null,"abstract":"The results of a study on the disposal of waste discharge at the iron and steel works using centrifugation and vacuum sublimation methods are presented. The object of the study was industrial effluents of titanium-magnesium production. The influence of centrifuge rotation speed, duration, temperature and fraction of solid phase on the process of industrial effluent separation into liquid (fugate) and solid (sediment) phases is studied. A complex of studies based on the multifactor experiment design was carried out to evaluate the effect of each of these factors. Optimum centrifugation parameters were established: rotor speed — 3000 rpm and duration — 30 min. The obtained solution (fugate) contained 195 mg/dm 3 of suspended matter, 26500 mg/dm 3 of chlorides, 39750 mg/dm 3 of dry residue, which indicates its high mineralization and the need for further purification. The expediency of a thermal method of fugate demineralization using a rotary vacuum evaporator was demonstrated in laboratory conditions. Optimum process parameters were determined: temperature 70 ° С , residual pressure — less than 50 mbar, duration — 30 min. Residue yield after vacuum sublimation was 6 % of the fugate weight. No suspended substances were found in the obtained condensate, and chloride content was 50 mg/dm 3 . The proposed technology for the disposal of industrial effluents at titanium-magnesium production will facilitate forming a closed water supply cycle at the enterprise. Residue obtained after the fugate vacuum sublimation containing mainly chlorides of alkali and alkaline earth metals can be recommended to use as an additive for the preparation of anti-ice materials, as well as drilling fluids and kill mud.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88928260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-22DOI: 10.17073/0021-3438-2019-1-67-74
Альфия Фаритовна Шарипова, Сергей Григорьевич Псахье, И. Готман, М. И. Лернер, А. С. Ложкомоев, Э. Ю. Гутманас
The paper states the results of obtaining Fe—Ag and Fe—Cu dense nanocomposites from composite powders consolidated by cold sintering in the high pressure gradient, as well as from nanosize powders of silver (Ag), iron (Fe) and copper (Cu). The results of mechanical tests conducted on Fe—Ag and Fe—Cu nanocomposites are provided. Nanocomposite powders were obtained by high energy attrition milling of carbonyl iron (Fe) micron scale powder and nanosize silver oxide powder (Ag2O), as well as iron and cuprous oxide (Cu2O) nanopowders. High resolution scanning electron microscopy was used to study the microstructure. Compacts featuring approximately 70 % of full density were annealed in hydrogen atmosphere to reduce silver and cuprous oxides to metals and to remove oxide layers from the surface of iron powder particles. This was followed by cold sintering — consolidation under high pressure at a room temperature. The data on specimen density dependence on pressure in the range of 0,25 —3,0 GPa were obtained. Densities were above 95 % of the full density for all nanocomposites, and close to 100 % of the full density under 3,0 GPa for Ag and Cu powders. High mechanical properties in three-point bending and compression were observed for all nanocomposites. It was found that mechanical properties of nanocomposites are substantially higher as compared with composites obtained from micron scale powders. Higher ductility was observed in Fe—Ag and Fe—Cu nanocomposites as compared with specimens obtained from nanostructured Fe.
{"title":"Cold sintering of Fe-Ag and Fe-Cu by consolidation in high pressure gradient","authors":"Альфия Фаритовна Шарипова, Сергей Григорьевич Псахье, И. Готман, М. И. Лернер, А. С. Ложкомоев, Э. Ю. Гутманас","doi":"10.17073/0021-3438-2019-1-67-74","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-1-67-74","url":null,"abstract":"The paper states the results of obtaining Fe—Ag and Fe—Cu dense nanocomposites from composite powders consolidated by cold sintering in the high pressure gradient, as well as from nanosize powders of silver (Ag), iron (Fe) and copper (Cu). The results of mechanical tests conducted on Fe—Ag and Fe—Cu nanocomposites are provided. Nanocomposite powders were obtained by high energy attrition milling of carbonyl iron (Fe) micron scale powder and nanosize silver oxide powder (Ag2O), as well as iron and cuprous oxide (Cu2O) nanopowders. High resolution scanning electron microscopy was used to study the microstructure. Compacts featuring approximately 70 % of full density were annealed in hydrogen atmosphere to reduce silver and cuprous oxides to metals and to remove oxide layers from the surface of iron powder particles. This was followed by cold sintering — consolidation under high pressure at a room temperature. The data on specimen density dependence on pressure in the range of 0,25 —3,0 GPa were obtained. Densities were above 95 % of the full density for all nanocomposites, and close to 100 % of the full density under 3,0 GPa for Ag and Cu powders. High mechanical properties in three-point bending and compression were observed for all nanocomposites. It was found that mechanical properties of nanocomposites are substantially higher as compared with composites obtained from micron scale powders. Higher ductility was observed in Fe—Ag and Fe—Cu nanocomposites as compared with specimens obtained from nanostructured Fe.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82603354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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